This invention relates generally to automatic washers and means for dispensing wash additives inside automatic washers at a designated point during their programmed cycles of operation. More particularly still, the invention relates to a centrifugally activated dispenser system having a means for ensuring complete dispensing of all wash additives added to the dispenser as well as automatic rinsing of the dispenser after dispensing.
A number of different types of dispensers for liquids in automated washing devices have been used heretofore. Among these are such differing approaches as electromechanical devices which require programmed remote actuation, as well as a number of what are essentially self-actuated devices of a primarily mechanical nature which respond to various conditions during the operation of the washing machine, often a predetermined agitator speed threshold, to dispense liquids at some given point during the washing process without the need for external control devices.
Centrifugally actuated dispensers are frequently encountered in the latter group, and a good example of such a device is that shown in U.S. Pat. No. 4,656,844, which is commonly owned herewith and which is hereby incorporated by reference. As discussed in that patent, centrifugal dispensers typically employ a cup-like first receptacle which is usually either mounted upon the agitator or secured to the basket of the washing machine. The liquid additive contained within the first receptacle is forced upwardly and outwardly along the receptacle walls as the rotational speed of the agitator or basket increases, typically during a spin cycle, until the point is reached where the additive escapes over the edge of the receptacle and is received into a second receptacle. When the basket slows down, the fluid works its way under the influence of gravity, to the wash basket to contact the wash load.
It is known that these types of fabric softeners have some drawbacks. Specifically, most liquid wash additives used in combination with the prior art dispenser configuration are formulated such that use over a period of time results in deposits of dried unused liquid accumulating at various places in the dispensers. To overcome this deficiency of the liquid dispensing devices, typically, wash additives dispensers have been configured to be removable from the laundry appliance so that they may be rinsed manually at periodic intervals to prevent the above described build-up. In an effort to address this type of problem, U.S. Pat. No. 4,186,573 discloses a laundry liquid dispenser which is positioned onto the rim of a rotary spin basket. Subsequent to the dispensing of the wash additive into the spin basket, the dispenser may pass beneath a water inlet source and, in this fashion, receive clean inlet water so as to rinse out the dispenser.
In addition to the above-described drawback, the inventors have found that some liquid additives, such as certain fabric softeners, being relatively viscous in comparison to other fabric softeners, do not dispense satisfactorily from the known centrifugal wash additive dispensers. These more viscous fabric softeners do not readily flow out of the above mentioned first receptacle into the second receptacle. Further, these highly viscous fabric softeners do not readily flow from the second receptacle into the wash basket under the influence of gravity. As a result, a substantial portion of fabric softener remains in the dispenser at the conclusion of the wash cycle. This remaining fabric softener may, during the period between wash cycles, slowly travel to the bottom of the wash tub such that upon subsequent use of the washing machine, this fabric softener may chemically combine with detergent placed in the wash basket to form an undesirable substance which may result in unsatisfactory wash performance.
None of the centrifugal liquid dispensing devices known in the art are constructed to overcome this problem of unsatisfactory dispensing of highly viscous wash additives. It would be a substantial improvement in the art, therefore, if a dispenser system were provided which overcame the problem of undesirable wash additive deposit accumulation over time and provided for satisfactory dispensing of wash additives regardless of viscosity.